Alejandro R. asked:
<does someone know what were exactly those "national banks"?
Claus:
It seems that Marx used three terms with more or less similar meaning: "national bank", "main or principal bank" (Hauptbank), and "central bank" (Zentralbank). When he used these terms, they were generally referring to the activities of a bank like the Bank of England, meaning the activities of handling the gold reserve of the nation and having the right to the issue of banknotes. I have found following passages in Capital vol. 3 (from International Publ.):
Ch. 25, p. 403-4: "... in most countries the principal banks, [which issue - CMG] notes, [as - CMG] a peculiar mixture of *national* and private banks actually have the the national credit to back them, and their notes are more or less legal tender; ...".
Ch. 28, p. 454: Here Marx refers to the problems resulting from the concentration of several reserve functions on one single gold reserve: "And in addition to all this comes 1) the concentration of the national reserve fund in one single * central bank* [in the German original Marx uses the term *Hauptbank*, i.e. *principal bank* - CMG] ...".
p. 457: "In so far as this demand for pecuniary accommodation is a demand for capital, it is so only for money-capital. It is capital only from the standpoint of the banker, namely gold (in the case of gold exports abroad) or notes of the *National Bank* , which a private bank can obtain only by purchase ..."
Then there is the passage of Ch. 32, p. 517, mentioned by Alejandro R.
Ch. 35, p. 572: "We have also omitted from consideration the function of the metal reserve as a security for bank-note convertibility and as the pivot of the entire credit system. The *central bank* [Zentralbank in German - CMG] is the pivot of the credit system. And the metal reserve, in turn, is the pivot of the bank".
Claus.